def test_dynamic_layer_output_shape(self):
max_sequence_length = 40
test_layer = position_embedding.PositionEmbedding(
max_length=max_sequence_length)
# Create a 3-dimensional input (the first dimension is implicit).
width = 30
input_tensor = tf.keras.Input(shape=(None, width))
output_tensor = test_layer(input_tensor)
# When using dynamic positional embedding shapes, the output is expected
# to be the same as the input shape in all dimensions - but may be None if
# the input shape is None there.
expected_output_shape = [None, None, width]
self.assertEqual(expected_output_shape, output_tensor.shape.as_list())
def test_float16_dtype(self):
# Create a 3-dimensional input (the first dimension is implicit).
sequence_length = 21
test_layer = position_embedding.PositionEmbedding(
max_length=sequence_length, dtype="float16")
width = 30
input_tensor = tf.keras.Input(shape=(sequence_length, width))
output_tensor = test_layer(input_tensor)
# When using static positional embedding shapes, the output is expected
# to be the same as the input shape in all dimensions save batch.
expected_output_shape = [None, sequence_length, width]
self.assertEqual(expected_output_shape, output_tensor.shape.as_list())
# The default output dtype for this layer should be tf.float32.
self.assertEqual(tf.float16, output_tensor.dtype)
def test_dynamic_layer_slicing(self):
max_sequence_length = 40
test_layer = position_embedding.PositionEmbedding(
max_length=max_sequence_length)
# Create a 3-dimensional input (the first dimension is implicit).
width = 30
input_tensor = tf.keras.Input(shape=(None, width))
output_tensor = test_layer(input_tensor)
model = tf.keras.Model(input_tensor, output_tensor)
# Create input data that is shorter than max_sequence_length, which should
# trigger a down-slice.
input_length = 17
# Note: This test explicitly uses a batch size of 1. This is to get around
# Keras' restriction on Model invocations: inputs are expected to have the
# same batch cardinality as outputs. In practice, this layer should be used
# inside a model, where it can be projected when added to another tensor.
input_data = np.ones((1, input_length, width))
output_data = model.predict(input_data)
self.assertAllEqual([1, input_length, width], output_data.shape)